20 Overlooked Tips To Stop Emails from Going to Spam in 2023

20 Overlooked Tips To Stop Emails from Going to Spam in 2023

Vladyslav Podoliako
Mar 13, 2023
Reading duration
20 min

Are you tired of crafting high-quality emails only to have them end up in the dreaded spam folder? We know it’s frustrating.

Unfortunately, even the most well-crafted messages are at risk of being filtered out. The average email deliverability rate is only 81%, meaning that nearly one in five emails never make it to the intended recipient.

And it
isn’t probably the first time you’ve read a post about how to prevent emails from going to spam. Heck, we’ve even written multiple posts on this and plan to write more.

But this guide is different. We've compiled 28 non-intuitive tips that are often overlooked but make a significant impact on your email deliverability. You'll not see something like "Always get permission from email recipients" or "Proofread your emails."

So, yes, most emails risk being marked as spam.  But that doesn't mean YOUR email will.

There’s only one drawback: You must invest effort and time. But it's worth it.

Article Walkthrough:

8 Essential Domain Setup Tips to Prevent Email Going to Junk Folder

Every successful email campaign NEEDS to start with a technical setup. (Not "needs" lowercase but "NEEDS" — all caps, loud and clear. With spam filters getting smarter, domain setup is that important).

Here’re essential domain setup checkpoints to cross off your list before you start your email outreach campaign: 

Ensure your domain name has a trusted extension

That's because spammers prefer the opposite: to acquire more domains and reach inboxes. Your sender reputation will be much better if you use domain extensions like ".com," and ".io" and web address abbreviations used for your country. The statistics show that the number one most trusted top-level domain (TLD) is .com.

(❗) Also, don't add numbers or special symbols to your domain name.

Top-Level Domains To Consider

 .com .io .org .net .ai .edu .gov (just FYI)

Secondary Domain Zones or Country Zones for Local Outreach

.co .de .ua .uk .usa

ICANN-Era Generic Top-Level Domains (Unrestricted, generic domains can be registered by anyone and for any purpose. Due to this, they have less credibility than internet top-level domains)

.biz .viajes .xyz .rest .agency .cf .fit .cn .email .run .tk .ml .fail .bible

Setting up the proper FROM line (as important as the subject line)

The "From" line is the first thing that the recipient sees.  In fact, the sender name is the key reason why recipients open (or ignore) your email. Test your From line by sending your campaigns from a person’s name, person + company, or from your CEO, and choose a custom From line depending on the goal of your email.

Let’s review some common formulas:

FIRST NAME + LAST NAME. The best approach to generating an email address is to add your first and last names to it. Yes, that's simple. Just put yourself in the shoes of your customer — usually, we have more trust in an email that looks this way "FirstName.LastName@CompanyName.com" than the generalized "Department@CompanyName.com."

Use it for cold email outreach and first follow-up messages. 

FIRST NAME  + COMPANY’S NAME. Using your FIRST NAME along with your COMPANY'S NAME can add a personal touch while still maintaining a professional tone. This approach is particularly effective for recipients who work in start-ups or as sales or marketing managers and expect emails from other businesses. But use this name carefully — such From lines still feel less personal and less intriguing, than the full name of a real person.

COMPANY’S NAME. It can make your email seem impersonal and uninviting, leading the recipient to assume that it's just another unsolicited bulk email sent by a machine. While this approach might be suitable for warm emails or product emails, it's best to avoid it for cold email outreach.

Setting up BIMI (what the heck is BIMI and why it’s important)

As BIMI, an email specification that adds your brand logo to your email messages, is slowly paving its way from testing to adoption (and is coming to Apple email), it's highly recommended that you enable BIMI for your email outreach. 

Why BIMI signifies your reputation and helps prevent your emails from going to spam? Because you can’t have BIMI record without DMARC implementation (if you need help with DMARC, we highly recommend Folderly's free online tool to generate DMARC record). Therefore, enabling BIMI for your email marketing is highly recommended if you haven't done so already. Check out the expert guidance on BIMI setup.

Although this settings isn’t obligatory, it creates additional security layers against attackers. So, the Folderly team recommends setting up BIMI to prevent what we call the death of your domain reputation. 

Setting a custom tracking domain

If you're using an email marketing service to send emails, each message will have a default URL and tracking code added to it to track how users interact with it (such as open and click rates). If you haven't created your own custom tracking domain, the email service will use shared tracking domains for all accounts. 

The danger here is that some spam filters may flag domains that are commonly associated with spam if your emails use the same tracking domain as spammy messages. Thus, to protect your brand's reputation, it's important to create your own tracking domain.

Staying CAN-SPAM Act compliant (+ a tricky opt-out tip)

CAN-SPAM Act Sets standards for sending commercial messages to inboxes. It ensures that all businesses, regardless of size or industry, must follow the same rules and standards when sending commercial emails.  

(❗) Compliance laws are constantly being developed and updated. In the USA, the federal government has opted for a sectoral approach, placing the responsibility of protecting citizens' personal data on each state legislature. Between 2021 and 2022, 4 more states: Virginia, Colorado, Utah, and Connecticut each passed their own privacy regulations.

Check these questions to prevent email from going to spam by staying CAN-SPAM Act compliant:

❓ Have you included a valid physical postal address?
❓ Is every contact on your list manually selected, and do you have explicit consent?
❓ Is your subject line clear and logically linked to the content?
❓ Is your “From” line accurate?
❓ Does your email have a clear opt-out form?

And here’s an insider’s tip from Folderly: to make sure you stay compliant without opt-out link in cold emails (which is not recommended practice), it is enough to write something like “Let me know if you don’t want to receive any message from me and the offer is not relevant.”

Regularly testing the mail server's address and domain 

Preventing emails from going to junk requires quick action and thorough research to ensure that poor deliverability doesn't ruin your campaign. That's why it's helpful to get professional help. With a professional email deliverability test you can quickly check your mail server's address and also check email health.  

So, if you're unsure how to tackle a pressing issue, contact the Folderly team for additional guidance and support. Check before you send to achieve your marketing goals with confidence.

Using corresponding ESP for outreach

It's crucial to take into account the rules and restrictions of various email service providers (ESPs) when creating email campaigns, as each one has its own requirements. For instance, the Outlook may not recognize images resized within the HTML code, which negatively affects email deliverability.

Tailor your emails to the ESPs used by your recipients. 

Besides, take this expert tip from Folderly webinar: if you have Microsoft servers and your recipients use Outlook or Microsoft, it's advisable to use Outlook to send emails to them.  

And, here comes the next step — using a dedicated pre-check to make sure all the media and text are displayed correctly on most devices people use. And dedicated means watching how it will be depicted in different ESP inboxes.

You can either pre-check your emails manually (sending them to your personal address) or use special tools provided by your ESP. 

Warming up your domain (manually!) with the right frequency and smart delay

As for sending frequency, you should start with sending a smaller volume of emails. Your task is to set the daily target volume and allow 8-12 weeks for warming-up activities. The exact term will depend on the rules of your provider, but on average, it takes 2–3 months. So you'll need some patience.

You must also check your email provider’s maximum daily sending limits – to never exceed them. For example, Google Workspace allows sending 2,000 cold emails, while Office365 boasts an incredible 10,000 messages per day.

When you send 500 emails from a newly-registered account, they'll end up in a spam folder. This will happen because that's exactly what spammers do – register email addresses and bombard users with junk.

Best recommendations from Folderly experts, tested in practice:

500 emails a day — general limit 
200 emails a day — for your cold outreach
200 emails a day — for your positive engagement (you can automate it with Folderly Spam Fix or any other tool) 
100 emails a day — your responses, forwarded messages etc.  

Also, not less important is smart emails delay. Folderly team recommends target at 180-200 seconds between emails.

5 Non-Intuitive Tips for Creating a High-Quality Email List 

Cleaning and updating the list is crucial since every lead has a certain lifecycle tweet, with databases naturally degrading by about 22.5% every year. 

Before we go deeper, here’s the essential rule to remember regarding your prospect list: as paradoxical as it sounds, less is more :) 

Using a double opt-in approach (or why less is more)

You'd better ensure that only product-interested clients are added to your email lists. Always. The safest and shortest route to succeed with the goal is to introduce a double opt-in feature.


It will also protect your domain from email phishing — people sometimes share fake or inactive emails just for the benefits a registered user may get. Usually, it takes a few minutes to complete, but the deliverability effects of such a simple deed are consequently significant.

Segmentation and 3-level personalization for your subscribers

The segmentation, if approached correctly, helps to understand different groups of clients on a deeper level. 72% of survey respondents expect the businesses they buy from to recognize them as individuals and know their interests (and want brands to demonstrate their investment in the relationship, not just the transaction).

Since knowledge is power, based on the gathered information about every segment, you can write emails that reverberate with the audience and push them toward positive decisions regarding your product or service.

Based on your marketing field, company's specialty, or any other factor, you can divide the user list according to the:

1 Pict (1)

Extra tip from the Folderly team: 3-Level Personalization

Simple personalization: Name, company name, title, company size
Deep personalization: Unique data intelligence points (recent funding, platform usage, sales team size, and events attended)
Creative personalization: Connected video or personalized content (FYI — this approach can be tricky and may result in being marked as spam) 

Although you cannot come up with deep and creative personalization for every client because it’s not scalable, simple (or basic) personalization is a MUST. Check out our post on email personalization best practices for 14 practical tips on how to customise your marketing efforts.

Verifying every contact with an email validation tool (contact scrubbing)

The higher the number of invalid addresses on your mailing list, the better the chances of ending up in the junk folder are. It’s because of increased hard bounces (and anything over 2% is considered problematic).

The Folderly team has rounded a list of the most reliable email verifiers as of 2023:

  1. Verifalia
  2. Bounceless.io
  3. Bulk Email Checker
  4. Email List Validation
  5. Neverbounce
  6. ZeroBounce
  7. DeBounce

Most of these tools work the same way – you upload a list of addresses you need to be verified, and the system performs an in-depth check and provides you with up-to-date information on each address. Some verifiers are designed to eliminate invalid and inactive addresses on the spot.

Regularly monitoring your subscriber's activity

Whether you like it or not, subscribers tend to become inactive for one reason or another. While as many as 31% of people change their email addresses within a year, others may simply become no longer interested in offered services. Also, often people opt in with email aliases and delete them later (check our detailed article on what are email aliases).

Thus, no matter how often you write to them, they won't act back.

It is advised to mark those recipients who haven't opened your emails over the past half a year inactive and consequently delete their addresses from your mailing list. You shouldn't erase those addresses straight away.

You may want to follow the given formulas before final termination:

2 Pic (4)

Asking subscribers to whitelist your email address

Along with email personalization sides open communication with the user. What does it imply? A variety of things, but before you move on, you may need to ask your subscribers to whitelist you to receive your emails. There's no need to be pushy about it. A humble request in your welcome email will do. You may want to provide a whitelisting guide for different providers so the reader does not need to Google it.

It is best to request whitelisting in your welcome email as the recipient is still genuinely interested in your offer. However, a gentle reminder may also be attached to a follow-up letter.

4 Tips for Email Content that Will Prevent Emails from Going to Spam

83% of B2B Marketers use email engagement as the metric to track content performance. The email content is one of the most valuable parts of your marketing campaign. Here’re 4 non-intuitive points to check before initiating a mailing session.

Offering a unique value proposition (UVP) in every email 

Imagine you spend 2 minutes reading an email during a busy day and got nothing interesting, valuable, or entertaining. You are likely to furiously hit “move to spam” and contribute to the unsubscribe rate growth, which is now an average of 0.15%.

You must offer undeniable value in each and every email you share with the client base. The trick about USP lies in referring to the client's needs first. Modern-day customers value sellers that care for them, and using that knowledge to your benefit is the key to success.

So, here’s an overlooked tips on adding UVP:
- ChangeWe” or “Our”  found in the email content to You” or “Your”
- Use social proof. 88% of consumers trust social proofs. Including social proof, such as testimonials from happy customers or statistics about your company's success, can help to build trust with your audience and encourage them to take action.
- Leverage scarcity and urgency in your UVP. Creating a sense of scarcity or urgency can be a powerful way to motivate people to take action.
- Test and optimize. As with any marketing strategy, it's important to test and optimize your UVP over time.
- Keep it simple and concise. Aim to communicate your key value proposition in just a few words or sentences.

We also recommend checking chatgpt email marketing prompts that will help you to automate the creation of your value proposition. 

Avoiding tricky spam triggers (more than just spam words)

This probably isn’t the first time you’ve read about spam trigger words. But did you know that even using specific symbols or ALL CAPS can trigger spam filters? So, here’s a list of potential spam triggers in your emails to avoid: 

  • ALL CAPS.  Never. Ever. Especially in subject lines. 
  • Links. Be careful with those — emails with links will likely trigger spam filters. If you still use them, remember that links should be shorter than 120 characters, and make sure they are neither broken nor blacklisted.
  • Attachments. Today, spam filters (and recipients) are particularly nervous about any attachments that come along with your email. 
  • Symbols. £, $, €, and '%' symbols are the quickest way to get caught up by spam filters.
  • And, for sure, spam trigger words. We hope this updated spam trigger words 2023 will paint you a clearer picture of how to improve email deliverability.

Must-follow recommendation from Folderly: To avoid spam filters, it's better to skip links, attachments, and images in initial emails. ALWAYS. Start with a short and engaging opening that sparks interest, and share case studies and other relevant information only when necessary. This way, clients won't be overwhelmed with irrelevant information. Your primary task is to “get into the door” and then you can try experimenting with the content.

Also, you can use online spam words checker to quickly spot spam-triggering words in your emails.

Combining the use of both plain text and HTML

As you already know, there are two main types of emails – HTML vs plain text. While the first option offers simplicity and straight-to-the-point appeal, the latter is about creativity and a unique approach to the marketed matter.

The truth is that present-day ISPs treat those senders better who combine both variants. The trick here is ensuring that your HTML copy is well-coded and contains no errors or broken tags. Otherwise, you will be sent to the spam folder sooner than you can spell 'email deliverability.' Also, make sure your email contains plain text, and give people an option to use plain text when receiving your newsletter.

Making subject lines concise and connected to the email body

It's important to have concise subject lines that are connected to the email body and straight to the point. Despite ever-present temptation, you shouldn't try and use misleading subject lines to trick your users into opening the letter.

An example of a subject line that brings a high conversion rate: Do you have the capacity for new clients? 

Reason why it’s successful: 

It’s short (up to 41 characters, a sweet spot according to the study)
It’s to the point and client-oriented
It has no symbols and emoji. The open rate of subject lines without emojis is better than those having emoji (21.94% compared to 20.45%)
✅ And, of course, every business would have a capacity for new clients :)

Also, do A/B testing until you find the bottom of the funnel. 

FYI: If fooled once, your subscribers won't ever treat your messages with trust, which may begin a dreaded downfall. So, leave this cheap trick with subject lines for your competitors :)

3 A/B Testing & Optimization Tips to Ensure 100 % Inbox Placement

Even the most perfect-looking email copy requires optimization. That's an unspoken rule of email marketing worth remembering if you want to prevent your emails from going to the junk folder.

Experimenting with A/B Testing and choosing only one metric

Small changes make significant differences. Utilizing A/B testing, you can quickly determine what works and what doesn't for your subscribers and increase their satisfaction rates. For instance, by evaluating the open rate, you may see that sending emails on Thursday is better than sending emails on Monday. Otherwise, you could keep sending emails on Monday and, in time, be blocked by recipients whose email inboxes are already overwhelmed every Monday. 

So, choose a metric to A/B test and enjoy the experiment.

❗ Test one thing at a time - e.g. test subject lines only. Otherwise, you might trigger spam filters. Besides, it'll be challenging to determine which of the 3 tested emails brings the most positive engagement while all 3 contain different points which inevitably affect your spam rates.

Setting a deadline for A/B testing

Setting a deadline for A/B testing is an important but often ignored tip in marketing. While A/B testing can be a valuable tool for optimizing campaigns, it's important to have a clear timeline and stick to it. Testing can drag on indefinitely without a deadline, leading to wasted time and resources. You don’t want that to happen. 

Sending user surveys about preferences

It can't be stressed enough how vital sender-recipient interaction is, not only when avoiding spam folders. 71% of consumers expect companies to deliver personalized interactions, and this is a significant number!

The best way to establish a strong bond is to ask your subscribers what they want. You can share quizzes and surveys about preferred products, frequencies, and content types. While some users want to receive weekly newsletters, others will be up for monthly promotions and so on.


Staying up to date with the changing trends

Keeping up with the uprising trends that come and go as we speak is vital. The truth is, something considered spam-free yesterday may be labeled as spam today, as spam filters become stricter in no time.

The only thing you can do is watch out for the upcoming trends and put them to use before the competitors do. Consulting Folderly guides and case studies may come of use, too.

Instead of Summary: Ask Yourself, "Would I?"

The average professional spends 28% of the workday on emails. Just imagine how annoying it’s to get emails with no or false value. So, every time you are about to launch a new email marketing campaign, you should ask yourself – If I had to read this email when I had other things to do, would I?' :) 

The answer will emphasize how great an email copy you've crafted so far. In case the answer is “no,” the chances that your readers will assume differently are slim, so you should keep perfecting the email (or not send it all).

We have highlighted many other vital points to ensure your letters won't end up in the junk folder. Most of them are closely connected. Thus, you must consider applying the integrated approach to reap the most benefits from your campaign. 

However, with the best email deliverability tools, you are not alone in fighting this battle (and we recommend checking our comprehensive guide with criteria on how to choose your perfect email deliverability service).

You can always reach out to Folderly's email deliverability platform to apply the most professional and result-oriented approach to the success of your email outreach crusade!

Vladyslav Podoliako
Vladyslav Podoliako
Founder & CEO
Vlad is a Founder & CEO of Belkins and Folderly, a series entrepreneur and investor with over ten years of management expertise in companies with 100 million evaluation. Vlad has years of experience building and growing service companies and SaaS startups in SalesTech and MarTech. He is skilled in creating successful businesses from the ground up and building top-notch teams that drive all ventures to the top of their industries.

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